I pieced together an itinerary JFK-SFO-PEK-SYD on UA and Air China. SFO-PEK is F and other flights are J. Layover in PEK is 23 hours. All awards are saver.
UAL web site is asking for 120,000 miles for this itinerary.....i believe correct "price" is 80,000 miles for F, so I plan to call UA and ask for this.